Prevention and treatment of allergic inflammation by an Fcγ-Der f2 fusion protein in a murine model of dust mite-induced asthma

The immunoglobulin E (IgE) high-affinity receptor Fc epsilon RI expressed on mast cells and basophils plays a critical role in triggering allergic disease. The co-aggregation of the Fc epsilon RI and Fc gamma RIIb receptors is inhibitory to Fc epsilon RI signaling and holds great potential for the treatment of IgE-mediated allergies. In China, is a common anaphylaxis trigger. Therefore, in this study, the Fc gamma RIIb-mediated immunomodulating activity of recombinant Fc gamma-Der f2 fusion protein was tested in a Der f2-allergic murine model. Following the treatment, bronchoalveolar lavage fluid (BALF) was collected to measure the expression of several Th1/Th2-type cytokines (IL-5, TNF-alpha, IL-12p70, IL-4, IL-10, IFN-gamma and IL-18) and histamine, while blood was used to detect the specific IgE and IgG-types anti-Der f2 antibodies, for measurement. In contrast to the saline-treated allergic mice, the levels of Der f2-specific IgE, cytokines and histamine were lowered in the Fc gamma-Der f2-treated allergic mice, in addition to the rare inflammatory cell infiltration in the airways and blood vessels revealed by histopathological examination. The recombinant Fc gamma-Der f2 protein was demonstrated to function as an effective immunotherapeutic agent, suggesting that chimeric human Fc gamma-allergen proteins could be used in the development of antigen-specific immunotherapy for human allergic diseases.